This invention relates to power regulator circuitry, and more particularly, to power regulator circuitry for powering loads on integrated circuits such as programmable logic device integrated circuits.
Integrated circuits such as programmable logic devices often contain voltage regulators. For example, voltage regulators may be used to control the magnitude of a power supply voltage. In on-chip applications such as these it is desirable for a voltage regulator to exhibit good performance without consuming an excessive amount of circuit real estate.
Programmable logic devices are a type of integrated circuit that can be customized in relatively small batches to implement a desired logic design. In a typical scenario, a programmable logic device manufacturer designs and manufactures uncustomized programmable logic device integrated circuits in advance. Later, a logic designer uses a logic design system to design a custom logic circuit. The logic design system uses information on the hardware capabilities of the manufacturer's programmable logic devices to help the designer implement the logic circuit using the resources available on a given programmable logic device.
The logic design system creates configuration data based on the logic designer's custom design. The configuration data may be loaded into programmable memory elements on a programmable logic device to program the logic of the programmable logic device so that the programmable logic device implements the designer's logic circuit. The use of programmable logic devices can significantly reduce the amount of effort required to implement a desired integrated circuit design.
A voltage regulator may be used to produce a power supply voltage for programmable memory elements on a programmable logic device. During device operation, the power supply voltage for the programmable memory elements may be subject to noise induced by nearby capacitively coupled core logic. The programmable memory elements may also be sensitive to the rate at which the power supply voltage at the output of the regulator is applied during operations such as powering up the device.
It would be desirable to be able to provide a voltage regulator circuit that is able to produce accurate and well-controlled voltages without consuming excessive amounts of circuit real estate on an integrated circuit such as a programmable logic device.